Fig. 2

Microglial response increased but saturated relative to ongoing amyloidosis during aging. Plots show cortical Standardized Uptake Value Ratio (SUVR) of [¹⁸F]-GE180 (TSPO-activity) (a) and [¹⁸F]-florbetaben (amyloidosis) (b) in APP-SL70 mice at different ages (B) APP-SL70 indicate increasing cortical amyloidosis and 18 kDa translocator protein (TSPO) binding during aging (c). Percentage change for both PET tracers between baseline and + 6.3 months as a function of baseline age in APP-SL70 mice and wt reveal an inverted U-shape for TSPO activity (quadratic fit, R = 0.69, p = 0.014 (d) but a linear positive association for amyloidosis in APP-SL70 (linear fit, R = 0.50, p = 0.048 (e). N = 17